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Full text of "Handbook Of Chemical Engineering - I"

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Western oils usually asphaltum base or a mixture of the two bases. The latter are difficult to use in internal combustion engines, but make good boiler fuels. With fair approximation,
B.t.u. per pound oil = 18,650 + 40(£ - 10)
Where, B = Baum6 hydrometer reading. If s = specific gravity, B = (140 -*• a) - 130. High boiler efficiencies are easily possible with fuel oil. The principal impurities to be avoided are moisture and sulphur. The latter, in some oils, is as high as 3 per cent.
Commercial products are derived from crude petroleums by fractional distillation at increasing temperatures:
Gasoline, 56°Be*. and upward; Kerosene, 44 to 49°Be\; Gas oil, solar oil, 35°Be.;
Lubricants and residuum, 28°Be\ and downward.
Fuel oil may be either a crude (from which it may be necessary to remove sulphur, silt, moisture and gasoline), a distillate (gas oil or solar oil) or a residuum.    The heat
FIG. 25.—Babcock & Wilcox boiler with Dutch oven.
value and also the ease of utilization depend on the density. In steam boiler work, any American oil down to 140Be". may be employed. The oils most available for oil engines are the "solar" and gas types. These are expensive. Mexican oil down to 18°Be". has been successfully used in high compression (300 Ib.) engines, but the cost of heating the oil by live stream is considerable. The possibility of using a new oil in an engine can be positively determined only by actual trial.
Besides the main storage (in large plants not in thickly settled sections) underground storage tanks are usually installed close to the boiler room. Burners should never be fed by gravity. The oil should be heated (usually to about 180°) before